This term is often confused with mung, which
probably was derived from it. However, it also appears the word munge was in common use in Scotland in the
1940s, and in Yorkshire in the 1950s, as a verb, meaning to munch up into a
masticated mess, and as a noun, meaning the result of munging something up
(the parallel with the
kluge/kludge pair is
amusing). The OED reports “munge” as an archaic verb meaning
“to wipe (a person's nose)”.